Person:
Book,
Wayne J.
Book,
Wayne J.
Permanent Link
Associated Organization(s)
Organizational Unit
ORCID
ArchiveSpace Name Record
16 results
Publication Search Results
Now showing
1 - 10 of 16
-
ItemSteerability in Planar Dissipative Passive Robots(Georgia Institute of Technology, 2009) Gao, Dalong ; Book, Wayne J.Steerability is intuitively the ability to change directions. In this paper, a formal definition is given for the steerability of a robot achieved either passively or actively. A dissipative passive robot uses only passive actuators such as brakes and clutches (a clutch is essentially a brake plus a gearbox) to redirect or steer operator-imposed motion by dissipating energy. While it has safety and ergonomic advantages, which are essential for human interactions, it also has difficulties in redirecting certain motions since passive actuators cannot add energy. The force generated from a passive actuator is used to measure the steerability. A steerability theorem was then developed for a manipulator with generalized passive actuators. The steerability analysis for an example diamond-shaped manipulator shows the difference in steerability when using only brakes or a combination of brakes and clutches. Further analyses show the difference comes from the ability of a clutch to change the direction of the generated force in the subject robot by altering the effective gear ratios
-
ItemSpeed Control and Position Estimation of Small Hydraulic Cylinders for Digital Clay Using PWM Method(Georgia Institute of Technology, 2004-07) Zhu, Haihong ; Book, Wayne J.Digital Clay is a new generation 3D computer input and output device for surface shape and haptic effects. The device consists of arrays of fluidically actuated cells under the control of valves connected to two pressure reservoirs in a manner ultimately suitable to an implementation in MEMS technology. At the current stage, it is very difficult to implement a tiny position sensor into the tiny cell. This paper presents a control method for the speed and position estimation and control for the cells of digital clay only using low cost pressure sensors and without using any position-sensing device.
-
ItemRobot vibrations(Georgia Institute of Technology, 2001) Book, Wayne J.The nature of robotic arms invites vibratory behavior while the function of robotic arms is heavily penalized by that vibration. Consequently, understanding and compensating for the tendencies of a robot to vibrate are of great importance. Robotic vehicles have less tendency to vibrate, although mounting an arm on a vehicle introduces new sources of excitation and compliance and new penalties for the simple solution to vibration, that is, adding mass to rigidize the arm structure
-
ItemTime-Delay Command Shaping Filters: Robust and/or Adaptive(Georgia Institute of Technology, 1999-09) Book, Wayne J. ; Magee, David P. ; Rhim, SungsooTime-delay command shaping filters for reducing the vibrational response of flexible systems are introduced and discussed. Special attention is given to the role played by robustness and adaptation in producing effective filters even when system parameters change. Results from several authors are used to compare and contrast these approaches.
-
ItemControl of flexible manipulators using vision and modal feedback(Georgia Institute of Technology, 1999-05) Obergfell, Klaus ; Book, Wayne J.Literature for end point measurement and control is reviewed. An integrated vision sensor for tip position and an optical deflection sensor are incorporated into the control of a hydraulically actuated, flexible two-link manipulator arm. Analysis and experiments provide a design procedure and performance evaluation. The design procedure is based on successive loop closure and the use of output feedback modified to maintain stability. Point to point positioning performance is improved over alternative controllers.
-
ItemAn investigation of a passively controlled haptic interface(Georgia Institute of Technology, 1997) Davis, Hurley T. ; Book, Wayne J.Haptic interfaces enhance cooperation between humans and robotic manipulators by providing force and tactile feedback to the human user during the execution of arbitrary tasks. The use of active actuators in haptic displays presents a certain amount of risk since they· are capable of providing unacceptable levels of energy to the systems upon which they operate. An alternative to providing numerous safeguards is to remove the sources of risk altogether. This research investigates the feasibility of trajectory control using passive devices, that is, devices that cannot add energy to the system. Passive actuators are capable only of removing energy from the system or transferring energy within the system. It is proposed that the utility of passive devices is greatly enhanced by the use of redundant actuators. In a passive system, once motion is provided to the system, presumably by a human user, passive devices may be able to modify this motion to achieve a desired resultant trajectory. A mechanically passive, 2-Degree-of Freedom (D.O.F.) manipulator has been designed and built. It is equipped with four passive actuators: two electromagnetic brakes and two electromagnetic clutches. This paper gives a review of the literature on passive robotics and describes the experimental test bed used in this research. Several control algorithms are investigated, resulting in the formulation of a passive control law. Several issues specific to controlling passive and/or redundantly actuated mechanisms are presented, and an algorithm for transforming general (active) controller commands into an appropriate set of passive actuator commands is presented. This algorithm capitalizes on the overlapping capabilities of the actuators and the enhanced control capabilities they provide for a passive device.
-
ItemA Teleoperation Testbed for Nuclear Waste Restoration(Georgia Institute of Technology, 1994-08) Book, Wayne J. ; Love, Lonnie J. ; Farah, MichelThis paper presents the design and operation of a new teleoperation testbed currently under investigation at the Georgia Institute of Technology. This laboratory will enable researchers to investigate a wide range of issues concerning nuclear waste restoration. The focus of the project is to determine what factors effect the performance of human interaction in teleoperation. These factors include an investigation of various robot control algorithms, the effect of unilateral and bilateral information flow, the role of compliance oflong reach arms in teleoperation, and the influence of various queues in training and performance. Experiments and preliminary results concentrating on the significance of audible sounds in teleoperation are presented.
-
ItemTransfer functions of flexible beams and implication of flexibilty on controller performance(Georgia Institute of Technology, 1994) Cetinkunt, Sabri ; Book, Wayne J.Dynamic behavior of many mechanical motion systems having distributed flexibility are described by linear partial differential equations, i.e. flexible beams, satellite appendages, plates. Understanding the open loop transfer function (poles, zeros, d.c. gain) is a prerequisite for a successful controller design. The open loop pole-zero patterns of a flexible beam (using its infinite dimensional model) are studied as a function of actuator and sensor locations. The physics of the flexible beam dynamics is discussed in order to explain the physical source and the meaning of zeros, and its implications in terms, of the limitations imposed on the maximum closed loop bandwidth achievable. Although the actual system dynamics involve an infinite number of modes, finite dimensional models are needed for the design of a real time controller. The accuracy of finite dimensional models using different mode shapes are compared from a controller design point of view.
-
ItemContact Control for Advanced Applications of Light Weight Arms(Georgia Institute of Technology, 1992) Book, Wayne J. ; Kwon, Dong-SooMany applications of robotic and teleoperated manipulator arms require operation in contact and noncontact regimes. This paper deals with both regimes and the transition between them with special attention given to problems of flexibility in the links and drives. This is referred to as contact control. Inverse dynamics is used to plan the tip motion of the flexible link so that the free motion can stop very near the contact surface without collision due to overshoot. Contact mus occur at a very low speed since the high frequency impact forces are too sudden to be affected by any feedback generated torques applied to a joint at the other end of the link. The effects of approach velocity and surface properties are discussed. Force tracking is implemented by commands to the deflection states of the link and the contact force. This enable a natural transition between tip position and tip force control that is not possible when the arm is treated as rigid. The effects of feedback gain, force trajectory, and desired final force level are of particular interest and are studied. Experimental results are presented on a one-link arm and the system performance in the overall contact task is analyzed. Extension to multi-link cases with potential applications are discussed.
-
ItemDirect Adaptive Control of a One-Link Flexible Arm with Tracking(Georgia Institute of Technology, 1989) Yuan, Bau-San ; Book, Wayne J. ; Siciliano, BrunoA robust tracking controller for a one-link flexible arm based on a model reference adaptive control approach is proposed. In order to satisfy the model matching conditions, the reference model is chosen to be the optimally controlled linearized model of the system. The resulting controller overcomes the fundamental limitation in previously published research on direct adaptive control of flexible robots that required additional actuators solely to control the flexible degrees of freedom. The nominal trajectory is commanded by means of a tracking control. Simulation results for the prototype in the laboratory show improvements obtained with the outer adaptive feedback loop compared to a pure optimal regulator control. Robustness is tested by varying the payload mass.